Notes on Diplonaevia (Discomycetes inoperculati), with special regard to the species on Juncaceae

The only monocotyledonous families that take members of Diplonaevia Sacc. (= Merostictis Clem.) are found to be Juncaceae, Cyperaceae (Caricoideae–Caricieae and Trichophorum ) and Poaceae (especially Nardus ). The presence or absence of stromatic, clypeus–like tissues is studied in several species and found to be very variable not only from species to species but also within individual species. The patterns of variation exhibited by the excipulum, the asci and the spores are also discussed. No less than ten species are known to grow on Juncaceae, eight on Juncus and two on Luzula. D. helicospora (on J. trifidus), D. hyperborea (on Juncus subgen. Alpini ) and D. savilei (on L. arctica ) are new species. New combinations are D. antaretica (Dennis) Nannf., D. junciseda (Schroet.) Nannf. and D. microsticla (Dennis) Nannf. Host ranges and distributions are also studied and discussed.